Selective 1,2‐Aryl‐Aminoalkylation of Alkenes Enabled by Metallaphotoredox Catalysis

Abstract

A highly chemo‐ and regioselective intermolecular 1,2‐aryl‐aminoalkylation of alkenes by photoredox/nickel dual catalysis is described here. This three‐component conjunctive cross‐coupling is highlighted by its first application of primary alkyl radicals, which were not compatible in previous reports. The readily prepared α‐silyl amines could be transferred to α‐amino radicals by photo‐induced single electron transfer step. The radical addition/cross‐coupling cascade reaction proceeds under mild, base‐free and redox‐neutral conditions with good functional group tolerance, and importantly, provides an efficient and concise method for the synthesis of structurally valuable α‐aryl substituted γ‐amino acid derivatives motifs.

Three‐Component Alkene Difunctionalization by Direct and Selective Activation of Aliphatic C−H Bonds

“…With the optimized reaction conditions in hand, the diversity of aryl halide coupling partners was firstly evaluated (Scheme 3). Ther eaction with aryl iodide gave 4 in 15 % yield, while aryl chloride and aryl triflate were inactive.Aryl bromides containing various synthetic valuable functional groups,s uch as ether (8,18), fluoride (9, 15 and 16), cyano (10), trifluoromethyl (11)and ester (12), were all tolerated in the Ni/photo-HATprocess.Notably,the presence of chlorine (13 and 16)o rb orate (14)o nt he aromatic ring did not interfere with the reaction efficiency, thus providing awealth of new opportunity for further functionalizations.N aphthyl bromide was perfectly accommodated to furnish 19 in 73 % yield. Interestingly,a lkenyl bromide was also found to be applicable to this reaction, albeit in lower yield (20).…”

Three‐Component Alkene Difunctionalization by Direct and Selective Activation of Aliphatic C−H Bonds

“…[17] This strategy can serve as ap owerful supplement, since the previously reported method failed to obtain target product. [18] Strikingly,ketone was also found to be effective substrate for this transformation, providing product that was selectively functionalized at the distal to the electron-withdrawing carbonyl moiety (47 and 48,5 4% and 58 %y ield, respectively). TMS 3 SiH, which is prone to form as ilyl radical, underwent three-component coupling reaction to obtain the desired organosilicon compound 49 in moderate yield with only 3equiv of TMS 3 SiH.…”

“…With the optimized reaction conditions in hand, the diversity of aryl halide coupling partners was firstly evaluated (Scheme 3). Ther eaction with aryl iodide gave 4 in 15 % yield, while aryl chloride and aryl triflate were inactive.Aryl bromides containing various synthetic valuable functional groups,s uch as ether (8,18), fluoride (9, 15 and 16), cyano (10), trifluoromethyl (11)and ester (12), were all tolerated in the Ni/photo-HATprocess.Notably,the presence of chlorine (13 and 16)o rb orate ( 14)o nt he aromatic ring did not interfere with the reaction efficiency, thus providing awealth of new opportunity for further functionalizations.N aphthyl bromide was perfectly accommodated to furnish 19 in 73 % yield. Interestingly,a lkenyl bromide was also found to be applicable to this reaction, albeit in lower yield (20).…”